Add get and pull

Signed-off-by: Rahix <rahix@rahix.de>

README.md

@@ -251,5 +251,11 @@ serialized using `OpenOS`'s `serialization` library.
 ### `Network:broadcast(msg_tbl)`
 Send a message to all connected nodes on the network.
 
+### `Network:pull(filter_func, timeout)`
+Block until a message arrives for which `filter_func` returns `true`.  The signature
+of `filter_func` is `function(addr, msg_tbl)`, similar to the callback given to
+`Network:start`.  If `timeout` is not `nil`, `pull` should return after the
+timeout expired as well.
+
 ### `Network:stop()`
 Close this connection and uninstall the message handler.

bc-tests.lua

@@ -216,4 +216,14 @@ function test_multinode_iters()
   assert_equal("miter2v", verbs[1], "verb-list incorrect")
   assert_equal("miter4v", verbs[2], "verb-list incorrect")
 end
+
+function test_get_network()
+  local bc1 = BaseControl:new()
+  bc1:register("getnw1", 123)
+  bc1:finalize()
+
+  local bc2 = BaseControl:new()
+
+  assert_equal(123, bc2:get("getnw1"), "wrong value")
+end
 -- }}}

bc.lua

@@ -41,6 +41,7 @@ function Network:new(modem, port)
   local self = {
     modem = modem or require("component").modem,
     port = port or Network.default_port,
+    event = require("event"),
   }
   setmetatable(self, {__index=Network})
 
@@ -56,7 +57,7 @@ function Network:start(callback)
     if port ~= self.port then return end
     callback(addr_remote, serialization.unserialize(msg))
   end
-  require("event").listen("modem_message", self.listener)
+  self.event.listen("modem_message", self.listener)
 end
 
 function Network:send(addr, msg)
@@ -67,8 +68,24 @@ function Network:broadcast(msg)
   self.modem.broadcast(self.port, serialization.serialize(msg))
 end
 
+function Network:pull(filter, timeout)
+  local last_msg
+  local ev = self.event.pullFiltered(timeout, function(ev, addr_lo, addr_remote, port, _, msg)
+    if ev ~= "modem_message" then return false end
+    if addr_lo ~= self.modem.address then return false end
+    if port ~= self.port then return false end
+    last_msg = serialization.unserialize(msg)
+    return filter(addr_remote, last_msg)
+  end)
+  if ev ~= "nil" then
+    return last_msg
+  else
+    return nil, "timeout"
+  end
+end
+
 function Network:stop()
-  require("event").ignore("modem_message", self.listener)
+  self.event.ignore("modem_message", self.listener)
   self.modem.close(self.port)
 end
 -- }}}
@@ -163,8 +180,23 @@ function BaseControl:get(noun, timeout)
     return self.local_nouns[noun]
   elseif self.local_verbs[noun] ~= nil then
     error("\""..noun.."\" is not a noun")
+  elseif self.remote_nouns[noun] ~= nil then
+    self.network:send(self.remote_nouns[noun], {
+      ty=Message.NounRequest,
+      noun=noun,
+    })
+    local answer, err = self.network:pull(function(remote, msg)
+      if remote ~= self.remote_nouns[noun] then return false end
+      if msg.ty ~= Message.NounResponse then return false end
+      if msg.noun ~= noun then return false end
+    end, timeout)
+    if answer == nil then
+      return nil, err
     else
-    return nil
+      return answer.value
+    end
+  else
+    return nil, "noun \""..noun.."\" unknown"
   end
 end
 
@@ -232,8 +264,16 @@ function BaseControl:_network_handler(remote, msg)
     for _, verb in ipairs(msg.verbs or {}) do
       self.remote_verbs[verb] = remote
     end
+  elseif msg.ty == Message.NounRequest then
+    self.network:send(remote, {
+      ty=Message.NounResponse,
+      noun=msg.noun,
+      value=self.local_nouns[msg.noun],
+    })
+  elseif msg.ty == Message.NounResponse then
+    -- Handled via pull
   else
-    error("TODO: Delet this")
+    error("TODO: MessageType Unknown")
   end
 end
 -- }}}